In a chapter in Cryptozoology and the Investigation of Lesser-Known Mystery Animals (2006), I noted two interesting sightings of possible bioluminescent spiders, both brought to the attention of science by American Museum of Natural History curator Barnum Brown, and then promptly forgotten by the scientific communitity. One was Brown's personal sighting in what is now Myanmar, and the second was detailed to him from a correspondent in India. I recently ran across another account, but from Australia. McKeown (1963) stated:

On 22 March 1940, I received a letter from a correspondent, Miss Elaine L. Chauncy, of “Bulliwallah,” Clermont, Queensland, in which she told me:

“About 10 o’clock at night, after it had been raining all day and had suddenly stopped, we noticed about half a dozen very bright little lights on the wall in a dark room, the lights came on at intervals of about a second. They were much the same as fireflies, and, as there were fireflies about we though they were, but closer investigation showed them to be very small spiders, with a body about the size of a split pea, and long thin legs. I have never seen this interesting little luminescent spider before or since, apparently it is very rare, as one never seems to hear much about it. . . .”

McKeown suggested that these could either be a new species, or might possibly involve spiders that fed on fireflies. As I noted in discussing the Barnum Brown accounts, however, Brown noted that because spiders do not devour solid food, but rather suck in enzyme-liquified material, it is unlikely that firefly prey would cause blinking abdomens. (And, of course, a number of fireflies produce chemicals distasteful to spiders and other predators.) If this were a likely scenario, I think it would be well-noted in the entomological literature by now. Another possibility that can't be ruled out so easily is infection by luminous bacteria or fungi.

Still, this is an interesting case, and would be easier to investigate than sightings in the forests of Myanmar and India. Australian researchers should keep an ear out for stories of these arachnids.